Rewarming the frostbitten areas

The frostbitten areas need to be rewarmed. Rewarming shouldn't be attempted until you're out of the cold.

If the warming process is started and the frozen parts are then re-exposed to the cold, it can cause further, irreversible damage.

Rewarming should ideally be carried out under medical supervision – it can be a painful process requiring painkillers and expert medical assessment. The best results are achieved using a whirlpool bath that contains a mild antiseptic.

The affected area should be rewarmed slowly by immersing it in warm, but not hot, water. A bath of water at a temperature of 40C to 41C (104F 105.8F) is recommended.

Rewarming should last at least 30 minutes and only be stopped once the affected body part is a red-purple colour and can be easily moved.

This process can be repeated twice a day until there are clear signs that the affected body part is beginning to heal, such as the growth of new skin and the return of normal skin colour.

Depending on the severity of pain, very strong painkillers, such as morphine, may be needed. Ibuprofen should also be taken as it has additional protective properties for frostbite.

After rewarming

After the frostbitten area has been thawed, it should be gently wrapped in clean bandages, with the fingers and toes separated. It's very important to keep the skin clean to avoid infection.

Too much movement should be avoided, and the limbs should be raised if possible. Avoid walking on affected feet and toes that have been rewarmed, as the tissues will be very delicate.

After rewarming, the skin will be discoloured and blistered, and will eventually scab over. If the frostbite is superficial, new pink skin will form beneath the discoloured skin and scabs. The area usually recovers within 6 months.

Severe frostbite

If you have severe frostbite, you'll need to be admitted to a specialist unit where medical staff are experienced in treating these types of injuries.

This is often a specialist burns unit because exposure to very high temperatures can cause the same type of injury as exposure to very cold temperatures.

If there's a very high risk of major damage, you may have thrombolytic therapy (tPA). Medication to help break up small clots in the frostbitten blood vessels will be given as injections or through a drip in your arm.

This should improve blood flow to the affected body part, which can stimulate healing and prevent further damage. You may also be given antibiotics to prevent the affected body part becoming infected.

Iloprost is sometimes used to treat very severe cases of frostbite. It works by widening the blood vessels that supply blood to the affected body part.

When severe frostbite threatens the loss of a limb, finger or toe, a person should be considered for treatment with tPA or iloprost within 24 hours of the injury occurring.

Experience has shown that treatment given within this timeframe has the best outcomes in terms of saving the affected body part.

But giving these treatments after 24 hours could still be considered to be an option at an experienced unit.

In the most serious cases, an entire part of the body, such as the fingers or toes, may need to be removed (amputated).

A decision to perform debridement or amputation is usually delayed for several weeks, as often what appears to be dead tissue can heal and recover over time.

Long-term effects

After having frostbite, some people are left with permanent problems, such as increased sensitivity to cold, numbness, stiffness and pain in the affected area.

Unfortunately, not much can be done to treat sensitivity to cold, numbness or stiffness. A medication called amitriptyline can sometimes be effective at controlling the pain associated with the long-term effects of frostbite.